Add notices for important api exceptions

[message-dimke]

Changes proposed in this Pull Request:

Adding an action to hook into Pinterest API exceptions to control Admin Notices. Adding an account failure notice into WooCommerce admin area in case there is a problem with the account while registering the feed (the most common scenario at the moment).

The note is dismissable and will show itself only once per connect-disconnect cycle. The note is removed on the disconnect event.

Detailed test instructions:

1. Download the extension and connect to your Pinterest account.
2. Edit the code lines below by adding a filter to emulate the request failure

pinterest-for-woocommerce/src/API/APIV5.php

Lines 524 to 530 in 1552a0f

	public static function create_feed( array $data, string $ad_account_id ): array {
	return self::make_request(
	"catalogs/feeds?ad_account_id={$ad_account_id}",
	'POST',
	$data
	);
	}

add exactly before the return statement:

add_filter(
	'pre_http_request',
	function ( $response, $parsed_args, $url ) use ( $ad_account_id ) {
		if ( "https://api.pinterest.com/v5/catalogs/feeds?ad_account_id={$ad_account_id}" === $url ) {
			return array(
				'headers'  => array(
					'content-type' => 'application/json',
				),
				'body'     => json_encode(
					array(
						'code'    => 2625,
						'message' => 'Sorry, you cannot perform this action as your account has been disapproved. Please see business hub for more details. https://www.pinterest.com/business/hub/',
					)
				),
				'response' => array(
					'code'    => 403,
					'message' => 'Forbidden',
				),
				'cookies'  => array(),
				'filename' => '',
			);
		}
	},
	10,
	3
);

3. Go to WooCommerce - Status - Scheduler Actions - Pending

4. Force run the pinterest-for-woocommerce-handle-feed-registration action.
5. Go to WooCommerce - Status - Scheduler Actions - Failed
6. Observe there is the failed action.
7. Observe there is an admin error notice duplicating the error of the action.

Changelog entry

Add - Admin notice of a failed Pinterest account status.